Garmin Oregon or Edge 800?

So, Santa was very kind this year and brought me a Garmin Oregon 450 GPS, and he even kept the receipt!

Question is, I'd been thinking about getting an Edge 800 and was wondering how they compare, has anyone used either/both? I like the fact that the Oregon runs on AA's so maybe better for multi-day trips, but the Edge seems more bike orientated.

Any opinions (what, on STW?) appreciated so I can decide on whether to keep or exchange.

I narrowed it down to the Dakota and Oregon with the Oregon winning due to screen size. Id tried a friends Dakota which I thought was good but plumped for the bigger screen which is easier to read whilst moving/glancing down approaching a junction.
The AA batteries were another reason due to multi day rides/bivi's with no way of charging.
For me the edges had too many limiting factors for my needs.

I have had all 3 and all excellent but have just gone back to the 800 just because the mount is better and the battery lasts all day even with the back light on,but for multi-day the oregon will be excellent as like you say you can just pop some battery's in,if you need a garmin discoverer full uk OS 1:50K map I have one for sale it's just plug and play so will work on any £45 posted.